One thing that becomes apparent when you look at the history of technology is how common having two different technologies force each other to develop is.
The best example of this is how during the middle ages both armor and weapons improved. Over the centuries this meant that there were times where having the best armor made you all but untouchable, and other times when a really good weapon could go through any armor you would face.
This is a good reason to have a technology be developed, or to keep being developed.